Set WatchdogSec=0 in Puma systemd unit template

The original template sets WatchdogSec=10, which causes systemd to kill
Puma if it remains silent for more than 10 seconds.

This commit changes WatchdogSec to 0 in our custom puma.service.erb,
disabling the watchdog feature. This prevents unwanted restarts and
avoids errors like:
> consul_puma_staging.service: Failed with result 'watchdog'

lib/capistrano/templates/puma.service.erb

@@ -16,7 +16,7 @@ After=syslog.target network.target
 
 [Service]
 Type=<%= service_unit_type %>
-WatchdogSec=10
+WatchdogSec=0
 <%="User=#{puma_user(@role)}" if fetch(:puma_systemctl_user) == :system %>
 WorkingDirectory=<%= current_path %>
 ExecStart=<%= expanded_bundle_command %> exec puma -e <%= fetch(:puma_env) %>